Common acute lymphoblastic leukemia-associated antigen (CALLA)-positive B cell lymphoma

We analyzed the expression of common acute lymphoblastic leukemia-associated antigen (CALLA) in 134 cases of non-Hodgkin's lymphoma of the B cell type using an immunohistochemical method. The incidence of CALLA expression in B cell lymphomas was higher in follicular lymphomas (29%) than in diffuse lymphomas (15%). Malignant lymphoma (ML), follicular small cleaved cell (FSC) according to the histologic type, showed a considerably high incidence of CALLA (43%), whereas ML, diffuse small cleaved cell (DSC) displayed a very low incidence (5%). These findings suggest the possibility that these two morphologically similar lymphomas may be derived from distinct populations of B cells [CALLA+-germinal center (GC) cells, CALLA- -germinal center (GC) cells or mantle zone (MZ) cells]. In addition, one case of DSC expressed surface immunoglobulin D (SIgD) and alkaline phosphatase (ALPase) as well as CALLA. This indicates that CALLA-positive small cleaved cell lymphoma expressing SIgD or ALPase may represent neoplastic proliferation of CALLA-positive MZ cells of secondary follicles in lymph nodes.